[ALSA] Fix compilation without CONFIG_PROC_FS

Memalloc module
Fix an error when built without CONFIG_PROC_FS.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/core/memalloc.c

@@ -655,8 +655,7 @@ static int __init snd_mem_init(void)
 
 static void __exit snd_mem_exit(void)
 {
-	if (snd_mem_proc)
-		remove_proc_entry(SND_MEM_PROC_FILE, NULL);
+	remove_proc_entry(SND_MEM_PROC_FILE, NULL);
 	free_all_reserved_pages();
 	if (snd_allocated_pages > 0)
 		printk(KERN_ERR "snd-malloc: Memory leak?  pages not freed = %li\n", snd_allocated_pages);